| [Backgroung]Detrusor underactivity(detrusor underactivity,DU)is a common urinary tract dysfunction.DU is defined by the International Continence Society(ICS)as"a contraction of reduced strength and/or duration,resulting in prolonged bladder emptying and/or failure to achieve complete bladder emptying within a normal time span".Even though urodynamic test has been considered the standard for DU diagnosis,no standard criteria were developed.Bladder contractility index(BCI)<100 or the maximum Watt Factor(Wmax)<7W/m2 was usually used to diagnose DU,however,a recent study from one German group showed that both BCI and Wmax continuously increased with rising obstruction grade,therefore,they thought it is not appropriate to employ a single threshold value for DU diagnosis in different bladder outlet obstruction(BOO)grade.They developed Maastricht-Hannover(M-H)nomogram with two parameters:bladder outlet obstruction index(BOOI)and Wmax,values below the 25th percentile line indicate DU,they claimed that with this new nomogram,DU can be revealed in BOO/BPH patients with every obstruction grade and can be used to study the effects of drugs or some treatment modalities on voiding function and predict the outcome of prostatic tissue ablation.However,this new nomogram has not been validated by other study groups.[Objective]In our study,M-H nomogram,Schaefer nomogram and Pdet@Qmax less than 40cmH2O were used to diagnose DU in BPH patients with lower urinary tract symptoms(LUTS).Our main purpose was to validate this new nomogram with our urodynamic measurements.[Methods]We retrospectively analyzed urodynamic measurements conducted between 07/2014-01/2017 in our department.Male BPH patients with LUTS were included in this study.Patients mean age was 66±3 years ranged from 50 to 79 years.BPH was diagnosed preoperatively by urosonography,prostate specific antigen(PSA),digital rectal examination and confirmed with pathological examination post-operation.Computer-urodynamic investigation was conducted by one experienced investigator.Immediately after free uroflowmetry measurement,the patient was asked at semireclining position,a 6-Fr transurethral double-lumen catheter was inserted into the bladder to determine post void residual urine(PVR),then the bladder was filled with warm(37?)sterile normal saline at a speed between 30-40 ml/min,and the intravesical pressure(Pves)was measured.pressure-flow measurement was recorded.Analyzed parameters include detrusor pressure at maximum flow(Pdet@Qmax),bladder obstruction index(BOOI,Pdet@Qmax-2Qmax),BCI(Pdet@Qmax+ 5Qmax)and Wmax.Bladder capacity at free uroflowmetry was calculated by adding voided volume and PVR.Voiding efficiency was calculated with the formula:(voided volume/bladder capacity)×100%.The Watts factor was calculated by the urodynamic machine.The Sigmaplot program(version 10.0)was used for data analysis.Unless stated,data were expressed as mean±standard error.P<0.05 was considered statistical significance.[Result](1)Both BCI and WFmax was increased with the rising of obstruction grade,BCI was increased from 63.5±+10.3 in grade 0 to 171.9±13.lin grade VI;Wmax was increased 6.1 ± 1.5 from in grade 0 to 24.6±4.7 in grade ?.(2)There was a higher coincidence rate of these three criteria in patients with BOO grade 0 to II,however,in patients with BOO grade III to VI,only M-H nomogram suggested the presence of DU.(3)Of these M-H nomogram suggested DU patients with BOO grade III-IV(n=49),the Pdet@Qmax was much larger than 50cmH2O,and 59%(29/49)had normal to strong detrusor contractility on Schaefer nomogram,59%(29/49)had Maximum Watt factor(Wmax)larger than 10 W/m2,57%(28/49)with bladder contraction index(BCI)larger than 100.[Conclusions]Our data suggested it is not appropriate to use M-H nomogram for DU diagnosis in patients with BOO grade III-VI.Wmax,BCI,projected isovolumetric pressure as well as Schaefer nomogram will still be the useful criteria. |
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